The present invention relates generally to an apparatus for holding a door or similar member in an open position for a predetermined period of time after which the door is returned to a closed position, and specifically relates to a pneumatic delayed action door holder.
A simple and inexpensive yet effective delayed action door holder has tremendous applications in both commercial and residential settings. For example, stores or other businesses may equip doors through which stock or merchandise regularly passes with such a holder in order to better accommodate its personnel by allowing the doors to remain open for an extended period, yet maintaining security by allowing the door to be closed after the goods have passed. Doors through which streams of people pass, such as those in churches, schools, or hospitals may also greatly benefit from such an apparatus. In addition, private residences, especially those in which an elderly or disabled person lives, may use such a device to allow that person the extra time necessary to safely pass through a doorway.
Means for delaying the closure of a door or the like have been attempted in the past. For example, U.S. Pat. No. 4,053,961 discloses the use of a suction pad which is attached to a door and which mates with a predetermined portion of the surface of an adjacent wall when the door is opened. The suction pad is caused to leak, either by holes provided in the pad itself o holes in that portion of the wall mating with the pad, thus eventually breaking the suction and allowing the door to close. Other attempts have been made for a suction cup provided on a door to temporarily mate with a second suction cup positioned on the wall, such as is described in U.S. Pat. No. 3,042,958. Such prior art however, suffers from distinct disadvantages since the suction pad must be adapted for attachment directly to the wall or to a mating member positioned on the wall, thus causing not only damage to the wall through the installation and continuous use of the device, but also requiring precise positioning of the suction pad relative to that portion of the wall with which it mates.
Still other prior art apparatus require extensive gearing, hydraulic cylinders, pistons, or the like to delay the closing of a door. However, the complexity and expense of these devices render them impractical in many applications.
Accordingly, it is an object of the present invention to provide an apparatus for holding open a door or similar member for a predetermined period of time after which the door is returned to its closed position. It is a further object of the present invention to provide a delayed action door holder which is simple and inexpensive in construction. It is a still further object of the present invention to provide a delayed action door holder in which the means for achieving the delay in the closing the door does not require the relative positioning of elements provided on the door and elements positioned on the wall adjacent the door.
To achieve the above and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the invention comprises a combination of elements including, for example, a suction pad mounted to the door; a plate mounted to the door; means for providing relative motion between the suction pad and the plate as the door is moved to a predetermined position, the plate contacting the suction pad to form a vacuum therebetween when the door or other similar member reaches the predetermined position, the vacuum retaining the door in the predetermined position; and means for controlling the duration of the vacuum.
Because the apparatus of the present invention readily mounts on the jam of a door, it is particularly useful for storm or screen doors which must be held open by the person entering the door while a second door is opened.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.